www.nature.com/scientificreports OPEN Impact of natural salt lick on the home range of Panthera tigris at the Royal Belum Rainforest, Malaysia Bryan Andrew Lazarus1, Azlan Che‑Amat2, Muhammad Muzammil Abdul Halim Shah1, Azwan Hamdan1, Hasliza Abu Hassim1,4, Farina Mustafa Kamal3, Tengku Rinalf Putra Tengku Azizan1, Mohd Hezmee Mohd Noor1,5, Noordin Mohamed Mustapha3 & Hafandi Ahmad1* Natural salt lick (sira) is a strategic localisation for ecological wildlife assemblage to exhibit geophagy which may act as a population dynamic bufer of prey and predators. Undoubtedly, many agree that geophagy at natural licks is linked to nutritional ecology, health and assembly places facilitating social interaction of its users. Overall, natural salt licks not only save energy of obtaining nutrient leading to health maintenance but also forms the basis of population persistence. The Royal Belum Rainforest, Malaysia (Royal Belum) is a typical tropical rainforest in Malaysia rich in wildlife which are mainly concentrated around the natural salt lick. Since this is one of the most stable fauna ecology forest in Malaysia, it is timely to assess its impact on the Malayan tiger (Panthera tigris) home range dynamics. The three‑potential home ranges of the Malayan tiger in this rainforest were selected based on animal trails or foot prints surrounding the salt lick viz (e.g. Sira Kuak and Sira Batu; Sira Rambai and Sira Buluh and Sira Papan) as well as previous sightings of a Malayan tiger in the area, whose movement is dependent on the density and distribution of prey. Camera traps were placed at potential animal trails surrounding the salt lick to capture any encountered wildlife species within the area of the camera placements. Results showed that all home ranges of Malayan tiger were of no signifcance for large bodied prey availability such as sambar deer (Rusa unicolor), and smaller prey such as muntjacs (Muntiacus muntjac) and wild boar (Sus scrofa). Interestingly, all home range harbour the Malayan tiger as the only sole predator. The non‑signifcance of prey availability at each home range is attributed to the decline of the Malayan tiger in the rainforest since tigers are dependant on the movement of its preferred prey surrounding natural salt licks. Thus, the information from this study ofers fundamental knowledge on the importance of prey‑predator interaction at salt lick which will help in designing strategy in rewilding or rehabilitation programs of the Malayan tiger at the Royal Belum Rainforest. Natural salt licks are mineral rich deposits that play a signifcant role in the ecosystem of the tropical rainforest. Similarly, the importance of salt lick in terms of physiological well-being of animals of plant-based diets is well documented1–6 and utilization should not be afected by sex and age categories. In addition, topography has been suggested to afect the accessibility of certain prey to utilize the salt lick due to the changes in mineral content of the salt lick area 2,7,8. 1Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. 2Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. 3Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. 4Laboratory of Sustainable Animal Production and Biodiversity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. 5University Agriculture Park, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. *email: [email protected] Scientifc Reports | (2021) 11:10596 | https://doi.org/10.1038/s41598-021-89980-0 1 Vol.:(0123456789) www.nature.com/scientificreports/ THAILAND UpperBelum Sungai Kejar home range N05o49.109o E101o26.541o Gerik, Perak 12.29km RoyalBelum Rainforest Sungai Tiang home range 10.84km N05o42.518o E101o27.288o Sungai Papan home range PENINSULAR N05o37.551o MALAYSIA o o E101 24.179 8km SINGAPORE Temenggor lake Jetty LowerBelum ; Latitude:5O42’37”N;Longitude: 101O31’56”E Figure 1. Te location of the Royal Belum Rainforest, Peninsular Malaysia and the tracked home range of tigers around natural salt licks. Map details: (1) Peninsular Malaysia: Te map was illustrated by the author of this manuscript. (2) Royal Belum Rainforest: Generated from GPS Coordinate (https:// www. gps- coord inates. net/); Latitude: 5°42′37″N; Longitude: 101°31′56″E. Salt licks are a determinant of herbivore density in the rainforest, which in turns infuence the density and distribution of predators 9–12. Predators hunt species according to the foraging theory with preference for large bodied prey which posed the least risk and minimal investment for energy 12,13. Tus, predators play an impor- tant role towards balancing the natural ecosystem 14 and exerting a profound efect on vegetation densities and communities of small vertebrate7. Soil consumption at natural licks is linked to the nutritional ecology and/or health of the users. Other than nutritional benefts, the salt licks also function as animal-assembly venues which facilitates social encounters 15,16. Terefore, the existence of natural licks in a particular habitat may reduce the costs of obtaining adequate nutri- tion, and/or maintaining health; and thus, may be fundamental to population persistence. Te Royal Belum Rainforest in Malaysia has been established as one of habitat for Malayan tiger and houses majority of others fauna species including the barking deer or muntjac (Muntiacus muntjac), sambar deer (Rusa unicolor), Malayan sun bear (Helarctos malayanus), Malayan gaur (Bos gaurus) and Asian elephant (Elephas maximus)1,2,17,18. In Malaysia, large bodied prey species such as the sambar deer, and smaller prey like the munt- jac and wild pig (Sus scrofa) have been described as the key ecological determinant of predators such as the Malayan tiger density and their potential habitat 19,20. However, prey populations in the tropical rainforests are known to be decreasing due to several factors such as widespread poaching, legal hunting for consumption and deforestation for timber21,22. Inevitably, these factors contributed towards the dilution of prey abundance over a large area in the rainforest, afecting the viability of the predators such as the Malayan tiger. Despite advances in the understanding of ecological factors determining prey-predator interactions, no study has investigated how salt lick and prey availability infuences the home-range of the Malayan tiger in Royal Belum Rainforest. Terefore, the aim of this study is to identify the dynamics of prey species at the natural salt lick infuencing the home range and possibly the declining numbers of the Malayan tiger at the Royal Belum Rainforest. Data generated from this study will unveil the current distribution of Malayan tigers near the salt licks at Royal Belum Rainforest which will enhance strategic measures in rewilding or rehabilitation of the Malayan tiger. Methodology Study site. Te study was conducted from August 2017 to August 2020 at the Royal Belum Rainforest, Gerik Perak, which is located on the central-north of Peninsular Malaysia. Tis 130-million-year-old tropical rainfor- est is located at latitude: 5o42′37″ N and longitude: 101o31′56″ E which is covered by 2990 km2 of lowlands and hill dipterocarp virgin forests 23. Tis rainforest is rich in fora and fauna which are characteristics of a typical rainforest of Peninsular Malaysia24. Te forest is divided into two areas, the Upper Belum area, which stretches to the Malaysia-Tailand border and the Lower Belum area covered by the Temenggor Lake (Fig. 1). Permit of data sampling in the Royal Belum Rainforest was approved by the Perak State Park, Malaysia, and Department of Wildlife National Parks (PERHILITAN) Peninsular Malaysia. Tree sampling areas or home ranges were chosen based on the precision of ecological objectives and responses metrics such as wildlife rela- tive abundance, presence of preferred prey (e.g. sambar deer, muntjac and wild pig) utilizing the saltlicks and the sighting of a predatory species (e.g. the Malayan tiger) in the area. Te information above was obtained Scientifc Reports | (2021) 11:10596 | https://doi.org/10.1038/s41598-021-89980-0 2 Vol:.(1234567890) www.nature.com/scientificreports/ Figure 2. Te placement of cameras around a natural salt licks in the Royal Belum Rainforest. Map details: Te background featuring a DEM-based image is from the ArcGIS sofware application (https:// www. esri. com/ en- us/ arcgis/ produ cts/ arcgis- deskt op/ overv iew) with GPS reference coordinate; Latitude: 5°42′37″N; Longitude: 101°31′56″E. from discussions with the local rangers and local indigenous people who are well versed on the forest ecology. Malayan tigers are generally solitary animals whose movement is dependent on its prey, thus the study assumes that areas containing salt licks might be home ranges of an individual Malayan tiger. Te frst sampling area at Sungai Tiang is located approximately 8 km from the jetty at the Lower Belum, Complex (Fig. 1). Tree salt licks namely Sira Kuak, Sira Batu and Sira Tanah were identifed at Sungai Tiang. Te second, at Sungai Kejar, located approximately 12 km from Sungai Tiang and is consisted of two salt licks, namely Sira Rambai and Sira Buloh. Te third, at Sungai Papan, has only one large salt lick which is Sira Papan. Camera trap setting. A total of 66 camera traps (LTL Acorn 5210) were placed at strategic locations to identify the frequency of wildlife appearances at all studied salt licks. Te number of cameras necessary for monitoring of wildlife at surrounding area of salt licks was in accordance to the size of sample area between 20 and 92 m 22,25. Each salt lick was tracked by three camera traps, whereas other eight camera traps were placed in areas around the salt lick to enhance the potential of capturing images of the tiger.